Analysis Of Stabilization And Seismic Response Of Long-Span Hybrid Arch Type Aqueduct Support Structure In Shanxi Provice

With the development of the bridge theory the needs of social development, bridge is developing toward long-span, multi-bridge and light. Hybrid arch bridge of steel tube and concrete filled steel tube is a new type of bridge. This structure has greatly reduced its weight Meanwhile it has reduced the structure of the center of gravity and lateral seismic reaction.So the structure has been widely applied to aqueduct support structure.However, with the increasing of span of structural system, structural seismic performance, stability issues have become increasingly prominent, as important factors controlling the design of the structure. Therefore, the research about antiseism and stability of the class structure seems to be very important.The paper choose Yellow River Diversion Water Pumping Irrigation Engin-eering for Beizhao as background, use long-span hybrid arch type aqueduct sup-port structure whose designed parameters meet the standard requirement as the research object and adopt finite element program "MIDAS" to study seismic pe-rformance and stability. The main content as follows:Firstly, to analysis self-vibration characteristics of the model which have built, it has concluded that the structural surface stiffness is less than in-plane, thestif-fness of skew parts more larger,vaults position stiffness relatively soft and it bel-ongs to medium rigid structure. And considering the arch rib stiffness, side beam stiffness and the influence of pillar stiffness and layout to natural frequency of vibration of structure, it shows that the increase or decrease of the rib stiffness makes little impact on natural frequency of vibration, natural frequency of vib-ration increases as side beams surface stiffness increases and arch rods long st-em rod with side support pole make also obvious influence on natural frequency of vibration.Secondly, to analysis seismic response spectrum and elastic time-history of long-span hybrid arch type aqueduct support structure.To consider the seismic response of consistent excitation of structure and discuss on the influence of sei-smic response of structure in vertical and horizontal coupling incentive.we have got internal force and displacement response of key positions of arch rib under the conditions of all sorts of earthquake.These results have been compared and analyzed.It is found that displacement which vaults produced is greatest under earthquake effect in three direction.Meanwhile, structure displacements are sim-ilar between in a double earthquake portfolio and under the earthquake effect al-one. In all sorts of earthquake effect, the arch rib produce the maximum compre-ssive stress which is far below the proportion limit of concrete filled steel tube. It explains that concrete filled steel tube combination material is in elastic stage and reliable.Thirdly,based on the stability theory,we analysis structure elastic buckling u-nder three conditions and make the nonlinear analysis considering the influence of initial defects. We obtain structure stable safety coefficient under geometricno nlinear effect by load force-displacement curve, which is carried on the elastic i-nstability process analysis.The results showed that safety coefficient of the linear eigenvalue buckling analysis is obviously big. Considering that the influence of initial defects is less smaller,but geometry nonlinear greatly influenced the struc-ture stability,it is concluded that we should consider geometrical nonlinearity in-fluence in the process of hybrid arch bridge stability analysis.